Flutter doc explorer bot

main.go

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"net/http"
	"os"
	"os/signal"
	"regexp"
	"syscall"

	"github.com/bwmarrin/discordgo"
	"github.com/jasonlvhit/gocron"
	"github.com/sahilm/fuzzy"
)

type index []struct {
	Name            string `json:"name"`
	QualifiedName   string `json:"qualifiedName"`
	Href            string `json:"href"`
	Type            string `json:"type"`
	OverriddenDepth int    `json:"overriddenDepth"`
	EnclosedBy      struct {
		Name string `json:"name"`
		Type string `json:"type"`
	} `json:"enclosedBy,omitempty"`
}

var searchStrings []string
var searchIndex index

func main() {
	directPattern := regexp.MustCompile("!\\[(.*?)\\]")
	searchPattern := regexp.MustCompile("\\?\\[(.*?)\\]")
	bot, err := discordgo.New("Bot TOKEN")
	if err != nil {
		panic(err.Error())
	}
	bot.AddHandler(func(s *discordgo.Session, h *discordgo.MessageCreate) {
		fmt.Println(h.Content)
		if h.Author.ID == s.State.User.ID {
			return
		}
		if len(h.Content) >= 21 {
			if h.Content[:21] == "<@462299661995343882>" { //Bot source
				bot.ChannelMessageSendEmbed(h.ChannelID, &discordgo.MessageEmbed{
					Title:       "ℹ️ Help",
					Description: "⚠️ These commands can be within a message, and there can be multiple per messages",
					Fields: []*discordgo.MessageEmbedField{
						&discordgo.MessageEmbedField{
							Name:  "![query]",
							Value: "Gives a direct link to the first result, and suggests 2 others related to 'query'",
						},
						&discordgo.MessageEmbedField{
							Name:  "?[query]",
							Value: "Shows the 10 first search results about 'query'",
						},
					},
					Footer: &discordgo.MessageEmbedFooter{
						Text: "Source: https://gist.github.com/miyoyo/e2e790646408bb67bda0ab2ce81f1632",
					},
				})
			}
		}
		for _, value := range directPattern.FindAllStringSubmatch(h.Content, -1) {
			matches := fuzzy.Find(value[1], searchStrings)
			if len(matches) == 0 {
				s.ChannelMessageSendEmbed(h.ChannelID, &discordgo.MessageEmbed{
					Title:       "Direct reference - " + value[1],
					Description: "Not found.",
					Color:       0xEE0000,
				})
			} else {
				selected := matches[0]
				if len(matches) > 1 && searchIndex[matches[0].Index].Type != "class" {
					if searchIndex[matches[1].Index].Type == "class" {
						selected = matches[1]
					}
				}
				s.ChannelMessageSend(h.ChannelID, "https://docs.flutter.io/flutter/"+searchIndex[selected.Index].Href)
			}
		}
		for _, value := range searchPattern.FindAllStringSubmatch(h.Content, -1) {
			matches := fuzzy.Find(value[1], searchStrings)
			fmt.Println(value[1])
			embeds := []*discordgo.MessageEmbedField{}
			setSize := 5
			if len(matches) < setSize {
				setSize = len(matches)
			}
			for _, result := range matches[:setSize] {
				embeds = append(embeds, &discordgo.MessageEmbedField{
					Name:  searchIndex[result.Index].Type + " " + searchIndex[result.Index].Name + " - " + searchIndex[result.Index].EnclosedBy.Name,
					Value: "https://docs.flutter.io/flutter/" + searchIndex[result.Index].Href,
				})
			}
			if len(embeds) == 0 {
				s.ChannelMessageSendEmbed(h.ChannelID, &discordgo.MessageEmbed{
					Title:       "Search results - " + value[1],
					Description: "Not found.",
					Color:       0xEE0000,
				})
			} else {
				s.ChannelMessageSendEmbed(h.ChannelID, &discordgo.MessageEmbed{
					Title:  "Search results - " + value[1],
					Fields: embeds,
				})
			}
		}
	})
	if bot.Open() != nil {
		panic("could not open bot: " + err.Error())
	}
	updateIndex(bot)
	go func(bot *discordgo.Session) {
		gocron.Every(1).Day().Do(updateIndex, bot)
		gocron.Every(30).Minutes().Do(func() { bot.UpdateStatus(0, "mention me for help.") })
		<-gocron.Start()
	}(bot)
	fmt.Println("FlutterDoc is now running.  Press CTRL-C to exit.")
	sc := make(chan os.Signal, 1)
	signal.Notify(sc, syscall.SIGINT, syscall.SIGTERM, os.Interrupt, os.Kill)
	<-sc
	bot.Close()
}

func updateIndex(bot *discordgo.Session) {
	bot.UpdateStatusComplex(discordgo.UpdateStatusData{
		Status: "idle",
		AFK:    true,
		Game: &discordgo.Game{
			Name: "updating search...",
		},
	})
	out, err := http.Get("https://docs.flutter.io/flutter/index.json")
	if err != nil {
		bot.ChannelMessageSend("446257816345378827", "Failed to update index: %s"+err.Error()) //Debug channel
		return
	}
	buf := new(bytes.Buffer)
	buf.ReadFrom(out.Body)
	json.Unmarshal(buf.Bytes(), &searchIndex)
	searchStrings = nil
	for _, value := range searchIndex {
		searchStrings = append(searchStrings, value.QualifiedName)
	}
	fmt.Println(searchIndex)
	bot.UpdateStatus(0, "mention me for help.")
}